contract vs promise

contract

verb
  • To make an agreement or contract; to covenant; to agree; to bargain. 

  • To enter into a contract with. 

  • To enter into, with mutual obligations; to make a bargain or covenant for. 

  • To draw together or nearer; to shorten, narrow, or lessen. 

  • To betroth; to affiance. 

  • To shorten by omitting a letter or letters or by reducing two or more vowels or syllables to one. 

  • To bring on; to incur; to acquire. 

  • To gain or acquire (an illness). 

  • To draw together so as to wrinkle; to knit. 

noun
  • An order, usually given to a hired assassin, to kill someone. 

  • An agreement which the law will enforce in some way. A legally binding contract must contain at least one promise, i.e., a commitment or offer, by an offeror to and accepted by an offeree to do something in the future. A contract is thus executory rather than executed. 

  • An agreement between two or more parties, to perform a specific job or work order, often temporary or of fixed duration and usually governed by a written agreement. 

  • The document containing such an agreement. 

  • A part of legal studies dealing with laws and jurisdiction related to contracts. 

  • The declarer's undertaking to win the number of tricks bid with a stated suit as trump. 

promise

verb
  • To commit to (some action or outcome), or to assure (a person) of such commitment; to make an oath or vow. 

  • To give grounds for expectation, especially of something good. 

noun
  • A transaction between two persons whereby the first person undertakes in the future to render some service or gift to the second person or devotes something valuable now and here to his use. 

  • A placeholder object representing the eventual result of an asynchronous operation. 

  • Reason to expect improvement or success; potential. 

  • an oath or affirmation; a vow 

How often have the words contract and promise occurred in a corpus of books? (source: Google Ngram Viewer )